add read-only mode for input

crates/core/src/input.rs

@@ -105,6 +105,8 @@ pub struct InputState {
     redo_stack: Vec<HistoryEntry>,
     /// Consecutive edits within this interval merge into one undo entry.
     group_interval: Duration,
+    /// When set, user edits are refused, focus, movement, selection and copy stay.
+    read_only: bool,
     /// The shaped line and element bounds, recorded during each paint,
     /// and shared with hit-testing and the IME geometry conversions.
     layout: Rc<RefCell<Option<InputLayout>>>,
@@ -135,6 +137,7 @@ impl InputState {
             undo_stack: Vec::new(),
             redo_stack: Vec::new(),
             group_interval: DEFAULT_GROUP_INTERVAL,
+            read_only: false,
             layout: Rc::new(RefCell::new(None)),
         }
     }
@@ -212,6 +215,19 @@ impl InputState {
         self.group_interval = interval;
     }
 
+    /// Sets whether user edits are refused.
+    pub fn set_read_only(&mut self, read_only: bool, cx: &mut Context<Self>) {
+        if self.read_only != read_only {
+            self.read_only = read_only;
+            cx.notify();
+        }
+    }
+
+    /// Whether user edits are refused.
+    pub fn is_read_only(&self) -> bool {
+        self.read_only
+    }
+
     /// Records `old_text` at `range` being replaced by `new_len` bytes.
     fn push_history(&mut self, range: Range<usize>, old_text: String, new_len: usize) {
         self.redo_stack.clear();
@@ -262,6 +278,10 @@ impl InputState {
 
     /// Reverts the most recent edit group (`cmd-z`).
     fn undo(&mut self, window: &mut Window, cx: &mut Context<Self>) {
+        if self.read_only {
+            return;
+        }
+
         let Some(entry) = self.undo_stack.pop() else {
             return;
         };
@@ -277,6 +297,10 @@ impl InputState {
 
     /// Reapplies the most recently undone edit group (`cmd-shift-z`).
     fn redo(&mut self, window: &mut Window, cx: &mut Context<Self>) {
+        if self.read_only {
+            return;
+        }
+
         let Some(entry) = self.redo_stack.pop() else {
             return;
         };
@@ -331,6 +355,10 @@ impl InputState {
         window: &mut Window,
         cx: &mut Context<Self>,
     ) {
+        if self.read_only {
+            return;
+        }
+
         if range.is_empty() && text.is_empty() {
             return;
         }
@@ -571,7 +599,8 @@ impl InputState {
 
         self.paint_text(origin, line_height, window, cx);
 
-        if focused && self.selection().is_empty() {
+        // A caret promises that typing lands there; in read-only it does not.
+        if focused && !self.read_only && self.selection().is_empty() {
             self.paint_caret(
                 origin,
                 caret_x,
@@ -640,7 +669,11 @@ impl InputState {
 
         let index = self.index_at_x(event.position.x);
 
-        if event.click_count == 2 {
+        if event.click_count >= 3 {
+            // A single-line field is one line: triple-click selects all of it.
+            let len = self.text.len();
+            self.select_range(0..len, window, cx);
+        } else if event.click_count == 2 {
             let start = previous_word_start(&self.text, index);
             let end = next_word_end(&self.text, index);
             self.select_range(start..end, window, cx);
@@ -748,7 +781,8 @@ impl InputState {
                 }
             }
             "x" if command => {
-                if self.copy_selection(window, cx) {
+                // Read-only refuses cut entirely, clipboard included.
+                if !self.read_only && self.copy_selection(window, cx) {
                     self.delete_selection(window, cx);
                     cx.stop_propagation();
                 }
@@ -774,6 +808,10 @@ impl InputState {
                 cx.emit(InputStateEvent::Submitted);
                 cx.stop_propagation();
             }
+            "escape" => {
+                window.blur(cx);
+                cx.stop_propagation();
+            }
             "tab" => {}
             _ => {
                 if let Some(text) = &keystroke.key_char
@@ -850,6 +888,10 @@ impl EntityInputHandler for InputState {
         window: &mut Window,
         cx: &mut Context<Self>,
     ) {
+        if self.read_only {
+            return;
+        }
+
         let range = range_utf16.map_or_else(
             || self.selection(),
             |range| utf16_range_to_utf8(&self.text, range),